1. Field of the Invention
The present invention relates to a two-wheeled motor vehicle, such as motorcycle, provided with an antilock brake system, in which an ABS-unit is mounted on a vehicle body frame.
2. Related Art
Hitherto, in a scooter-type two-wheeled motor vehicle, which may be called “motorcycle” hereunder, in which a low-floored footrest is provided between a handle-bar and a seat, an ABS-unit of an antilock brake system is normally located in the vicinity of a head pipe at the front end of a vehicle body frame, in particular, in front of the head pipe, such as disclosed in Japanese Unexamined Patent Laid-open Publication No. HEI 9-216547 and No. HEI 11-314589. This arrangement is determined in consideration of the weight distribution between the front and rear portions of the motorcycle, reduction of the length of brake pipes, and so on.
However, in an arrangement in which the ABS-unit is arranged in front of the head pipe, a front cowl covering the front end of the vehicle body needs to be expanded so as to accommodate the ABS-unit. Moreover, in order to avoid interference with the rotation range of a front fork, the ABS-unit protrudes forward because it must be arranged in front of the head pipe at a certain distance therefrom. As a result, the front cowl suffers from considerable design constraints.
If the ABS-unit is arranged behind the head pipe in consideration of the matters mentioned above, it is difficult to secure sufficient space to accommodate the ABS-unit in view of body frame components. This not only causes difficulties in attaching and removing the ABS-unit in a case of trouble or the like, but also causes difficulties in installing of general rubber brake hoses having large diameters. However, use of small-diameter metal brake pipes causes further difficulties in attaching and removing the ABS-unit. Moreover, vibrations of the ABS-unit during its operation cannot be fully absorbed only by the metal brake pipes and are transmitted to the body frame, thereby causing discomfort to the rider.